Question

I have a class that contains a vector:

class Foo {
  typdef std::vector<int> Vec;
  Vec m_kids;
  void addKids(Vec::const_iterator begin, 
               Vec::const_iterator end) {
    m_kids.insert(m_kids.end(), begin, end);
  }
};

Is there any way to allow the following concise function calls? (Maybe by changing the addKids function above?)

int main() {
  Foo foo;
  foo.addKids(23,51,681);             // these...
  foo.addKids(3,6,1,4,88,2,4,-2,101); // ...would be nice?!
}

I suspect you can do it with C++0x vector initializer lists? But unfortunately, I cannot use C++0x. I can use Boost, though, if that helps.

Answer 1

You can do this:

Foo foo;
foo << 3, 6, 1, 4, 88, 2, 4, -2, 101; //inserts all!

For that you’ve to overloaded << and , operators, as:

class Foo {
  typdef std::vector<int> Vec;
  Vec m_kids;
public:
  Foo& operator<<(int item) {
    m_kids.push_back(item); return *this;
  }
  Foo& operator,(int item) {
    m_kids.push_back(item); return *this;
  }
};

Once you implement this, then you can also write:

foo << 3 << 6 << 1 << 4 << 88 << 2 << 4 << -2 << 101; //inserts all!

Even this,

foo, 3, 6, 1, 4, 88, 2, 4, -2, 101; //inserts all!

Or mix both as:

foo << 3, 6, 1 << 4, 88, 2 << 4 << -2, 101; //inserts all!

//and this too!
foo,3 << 6, 1 << 4, 88, 2 << 4 << -2, 101; //inserts all!

All are same!

But mixing doesn’t look good. My preference is the very first one!